Drawing material



T. S. REESE DRAWING MATERIAL Jan. 2, 1951 Filed Aug. 6, 1945 Ammo/0[OAT/N6 659mm 19 70am IN VEN TOR.

THOMAS 5. R5555 gwizqwm Arrow/var:

Patented Jan. 2, H351 DRAWING MATERIAL Thomas S. Reese, UniversityHeights, Ohio, as-

signor to The Di-Noc Company, Cleveland, Ohio, a corporation of OhioApplication August 6, 1945, Serial No. 609,113

. '3 Claims.

- This invention relates to drawing materials and more particularly totranslucent sheet ma terial suitable for drafting purposes.

- For many engineering purposes, it is necessary to make large drawingswhere high degrees of accuracy are essential. For example, the drawingsused in the manufacture of aircraft may be of very large size and mustbe extremely accurate. This is particularly true of drawings utilized inthe manufacture of templates which i are reproduced photographically onmetal and the photographically reproduced lines used in cutting thetemplates out of metal. Ordinary drawing materials, such as vellumpaper, tracing cloth and ordinary blue print paper are completelyunsuited for such purposes because they change in size with changes inatmospheric conditions, being particularly sensitive to changes inhumidity. For this reason it has heretofore been necessary to make thedrawings for such pur poses on large glass or metal plates. Both typesof plates are difficult to work on and difficult to handle, and glassplates. which are required where photographic reproductions are needed,are fragile and very heavy, requiring special equipmen for theirhandling.

It is therefore one of the objects of the present invention to provide aflexible sheet material suitable for drafting purposes which is light inweight, relatively inexpensive and whichv has a high degree of stabilityunder varying atmos-- pheric conditions. Another object of the inventionis to provide such a drafting materialwhich has a surface adapted totake pencil or ink markings and on which fine lines can be drawn with ahigh degree of accuracy. Another object is to provide such a drawingmaterial which has a surface-such that with reasonable care, lines canbe erased and redrawn easily and without substantial loss in sharpnessor accuracy. A further object is the provision of such a drawingmaterial which has a surface to which blue print solution can be appliedand to which the solutionwill, adhere in the subsequent development.

Further objects and advantages of the invention will become apparentfrom the following description of preferred forms thereof, referencebeing made to the accompanying drawing in. which the figure is adiagrammatic representation of a sheet of drawing material madeaccording to the present invention with the thickportion.

invention, the drawing material is made up of a sheet of clear ortranslucent plastic composed of a material having a high degree ofdimensional stability under varying atmospheric conditions oftemperature andhumidity and coated with a thin film of a differentresinous or plastic material, the film adhering firmly to the basematerial and having incorporated in it an abrasive flatting agent whichgives the coating a matte surface and a tooth to enable it to takepencil and ink markings and also properly to receive and retain blueprint solution. Prefer-'- ably the'base material is a sheet ofthermoplastic resinous material of vinyl type. Such materials, which arepolymers of vinyl chloride or copolymers of various vinyl compounds arereadily available on the market, suitable materials being sold in sheetform by Carbide and Carbon Chemicals Corporation under the trade nameVinylite and by the B. F. Goodrich Company under the trade name Geon.The sheets are composed of suitable vinyl resins formulated withplasticizers and the like so that the material can be made into sheetform with sufficient flexibility to permit bending without fracture.Preferably the base material is used in sheets having a thickness ofabout 0.010 inch. Vinylite plastic sheets No. VU-l310 (clear,calendered) and No. VU-3300 (translucent, white), marketed by Carbideand Carbon Chemicals Corporation and which are copolymers of vinylchloride and vinyl acetate, have the desired combination of sufiicientflexibility and dimensional stability under, varying temperature andhumidity conditions.

As furnished by the plastic manufacturers, the sheets have a smoothcalendered surface on one side and may have either a calendered or arelatively uneven, rough surface on the other side.

The sheets with one uneven surface are trans- 'Accordingto a preferredform of the present.

lucent, rather than transparent, the roughened side of the sheets havingthe appearance of obscure glass. The characteristics of both surfaces,however, are such that they will not take pencil or ink markings in asatisfactory manner, nor can they be coated with photographic materialssuch a blue print solution; in fact, one of the characteristics of vinylplastics is the difficulty of securing satisfactory adhesion of othermaterials thereto. e

I have found that resinous materials known as acryloids (i. e., acrylicesters and methylacrylic esters) have the property of adhering firmly tovinyl resin sheets and also can-be' given a surface suitable fordrafting purpos s. Accordingly, in order to provide the; yinyl sheettion. In order to give the coating the required matte finish and tooth,the acryloid coating material also includes a fiatting agent whichpreferably consists of finely divided diatomaceous earth, although otherfiatting agents such as magnesium carbonate, zinc stearate, aluminumstearate, silica flour and the like may be ens-- ployed if desired. 7

Suitable formulas for the coating material are as follows:

Example 1.--A formula embodying an acryloid' of the acrylic ester type.

Material: Parts by weightv Acryloid B-"I3 10 Aroclor #5460 4.

Toluol 8 Xylol 2- Diatumaceous earth 5.

Emample2.A formula embodying an acryloid" oftlie'methylacrylic estertype.

Material: Parts by weightv Acryloid A-l l0 Xylol 2- Diatomaceous earth 2trample 3.--A formula embodying'an acryloid of the' acrylic ester typeand Intro-cellulose.

Material? Parts by weight Acryloid B-73 M", 5 25% solution of R. S.nitro-cellulose in 50% butyl acetate and 50% toluol Aroclor #5460 4Toluol -.l- 8

Xylol 2 -Diatomaceous earth u 5 Acryloid 3-73 is a 40% solution ofacrylic resin in toluol, supplied by Resinous Products Co..Philadelphia,v Pennsylvania.

Acrylcid A-lO is a 30% solution of methacrylate resin in ethylene glycolmonoetlwl ether' acetate, supplied by Resinou-s Products Co.,Philadelphia, Pennsylvania.

Aroclor #5460 is' a solid resin consisting of a mixture of chlorinateddiphenyls, supplied by Monsanto Chemical Co., St. Louis, Missouri.

Inthe drawing, the base material, which is preferably composed of avinyl resin sheet, is indicated at H} while the coating material isindicated at ll. The thickness of these materials is greatly exaggeratedin the drawing and the thickness of the coating with respect to the basematerial'is probably greater than it would be in practice. The shadingon the surface of the coating is intended to indicate diagrammaticallythe matte finish produced by the flatting agent, which enables thecoating to take the variousdrafting materials.

The above coating materials can be applied readily by spraying, rollcoating or dipping, and

when applied in layers preferably about 0.001

inch in thickness, give the underlying basema The surface also hassufficienttooth and hardness to enable it to take pencil markings with ahard drafting pencil (5H, for example). The surface is level and fine,with the result that the lines are accurate and can be drawn easily, andthe abrasive quality of the surface is such that black lines can be madewith hardpencils without excessivepressure. As the flattin agent extendsthroughout the thickness of the coating material, lines or markings canbe erased from the surface of the coating, and the erased parts can bedrawn over again so long as the erasing has not removed the entirecoating. The surface is such that it will take markings of India orother inks, and blue print solution can be flowedsmoothly on the surfaceand will ad here thereto during the subsequent developing operation.

While 1 preferably employ translucent sheet material as described abovein the manufacture of my drawing material, it will be understood thatfor some purposes it may be desirable to employ opaque sheeting and forother purposes it is desirable to employ sheeting which is calendered'on both sides so-that it is transparent rather than translucent. Variouscoloring materials also can be incorporated in the plastic sheeting toprovide tinted transparent, translucent or opaque base materials; WhileI preferably employ resinous materials of the vinyl type, it will beunderstood that other plastic sheet materials having the desireddimensional stability may also beemployed within the broad teachings ofmy invention;

Because of the great dimentional stability of the underlying basematerial, drawings can bemade upon my material with a high degree ofaccuracy, and the original accuracy of the drawing will be maintainedregardless of substantial changes in atmospheric conditions. Thusdrawings made on my material can bereproduced accurately by photographicmethods. The material is light in weight as compared toglass platespreviously employed and is strong and flexible so that it can be shippedand handled without damage and without requiring any specialprecautions. The material can be produced at relative low cost becauseof the ease with which the'coating operation can be carried out. Thenature of the coating material is such that it' adheres permanently tothe underlying vinyl base, while itssurface is such that it will readilytake all'of the materials ordinarily used in drafting work, includingpencil markings, inks and blue print solution.

Those skilled in the art will appreciate that various changes andmodifications may be madev in my invention without departing from thespirit and scope thereof. Therefore. it is to be understood'that mypatent is not limited to the preferred form of my inventiondescribed'herein or inany manner other than by the scope of'the appendedclaims.

I claim:

1. Drawing material comprising a sheet of thermoplastic resinousmaterial consisting mainly of a vinyl polymer which sheet is highlyresistant to dimensional changes by atmospheric influences: and whichhas firmly adhered thereto a coating agent" on the-basis of thetotalsolids" deposited,

being adapted to take pencil markings by virtue of the tooth imparted toit by the flatting agent. being adapted to take blue print solution, andhaving the surface appearance of finely ground glass.

2. Drawing material comprising a sheet of polyvinyl chloride which sheetis highly resistant to dimensional changes by atmospheric influence;

and which has firmly adhered thereto a coating a of an acrylic resin,said coating being derived from a dispersion of the resin in a volatileliquid vehicle containing a finely divided abrasive fiatting agent whichextends throughout and imparts a tooth to the coating, being comprisedof from roughly one-third to roughly one-half of fiatting agent on thebasis of the total solids deposited, being adapted to take pencilmarkings by virtue of the tooth imparted to it by the flatting agent,being adapted to take blue print solution, and having the surfaceappearance of finely ground glass.

3. Drawing material comprising a sheet of vinyl chloride-vinyl acetatecopolymer which sheet is highly resistant to dimensional changes by at-fmospheric influences and which has firmly adhered thereto a coating ofan acrylic resin, said coating being derived from a dispersion of theresin in a volatile liquid vehicle containing a finely divided abrasivefiatting agent which extends throughout and imparts a tooth to thecoating, being comprised of from roughly onethird to roughly one-half offlatting agent on the basis of the total solids deposited, being adaptedto take pencil markings by virtue of the tooth imparted to it by theflatting agent, being adapted to take blue print solution, and havingthe surface appearance of finely ground glass.

THOMAS S. REESE.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 1,934,824 Schwalbe Nov. 14, 19332,253,562 Hinman Aug. 26, 1941 2,292,393 Mitchell Aug. 11, 19422,292,539 Nichols Aug. 11, 1942 2,312,623 Brooks Mar. 2, 1943 2,360,650Crane Oct. 17, 1944

